1. Field of the Invention
This invention relates to a method of preventing tarnishing of a polished glass article during storage.
2. Description of the Prior Art
Recently, most glass articles have been used after applying various types of metal, metal oxide or fluoride coatings to the polished surface of the glass articles. However, tarnishing of the polished surface of the glass article often occurs during storage before applying the coating, and the cause of the tarnishing is a most serious problem to be solved.
If the coating is applied on even a slightly corroded surface of the glass article, the defect shows up clearly due to the interference phenomenon, and, in a typical case, the coating peels off. Tarnishing to an extent which influences the coating of the glass occurs in an unexpectedly short period of time on some types of glass. For example, tarnishing occurs in atmospheric air only several minutes after the polishing, washing and drying treatments, for some types of glass, and, in some cases, the application of the coating becomes impossible.
Accordingly, polished glass can not be stored for a long period of time before the coating is applied, and the flexibility in production of coated glass articles is therefore greatly restricted.